Thiel Owners

The 2 large conical shapes, one smaller than the other, by appearance don’t seem to align symmetrically which I think is a good thing. The stepped alignment of the cone segments themselves would reduce a polarity of shear from traveling and returning back into the cone and again becoming a part of the next signal. Purify drivers have a stepped surround which I believe serves a similar though unintended purpose for reducing shear wave interference. A shear wave can only travel thru solids and travels in 2 directions until it collides into another and splits again and again. That is why the grill frame material and shape is important and can be heard when the style is changed, or when the grille is removed. This wave action and their collisions is generally not well understood but is used in the study of seismology and should be used in acoustic design and implementation... TomD

Happy Friday! All

I've been looking at / listening to grille effects on the SCS4. It is somewhat eccentric in that it has no fabric and the full-baffle is covered by a perforated steel mesh that is quite transparent. The electrical / magnetic fields meter shows that the intense fore-aft fields through the center of the coax are modulated by the metal grille. The EMF changes shape (becomes wider), but most notably, the electrical field is reduced by an order of magnitude in front of the grille. Back fields are unaffected. With my head a foot in front of the coax, I can hear a slight lifting of a veil by removing the grille. I would call this change so slight as to be barely noticeable. Other products may differ. My high-frequency hearing is far from what it was. So others may hear more difference. With all this pesky learning I would remove the grilles while listening.

Over the years that seems to be common among reviewers and listeners. I always attributed that to the fabric, but it seems there are other elements involved.

I removed the steel door that covers my breaker panel box which is located in my audio room. With 2 friends present I did a door on door off  listening test. Obvvious improvement every time with panel off. Steel will alter the flux field as a signal travels a copper wire. Same as I found replacing steel fasteners with brass holding drivers ,tweeters ,crossovers and circuit board  fasteners.. Any ferrous material will bend or alter a signal path . Generates interfering energy. TomD

Tom - Thiel had gone to non-magnetic (stainless steel) screws by 2007 SCS4. I don't know when / which other products migrated to non-magnetic screws. I had verified (and taken to heart) your observation regarding non-ferrous connectors.

Today's biggest (repeat) lesson is that XO networks don't belong behind a driver, whether shielded or not.